In a conventional magnetic retainer, e.g. a magnetic base, adapted to be magnetically secured on a magnetizable object, a limited size of its base member has considerably restricted the magnetic attraction attainable between a permanent magnet accommodated therein and the object. The use of a larger base member in an attempt to increase the magnetic attraction renders the whole assembly undesirably heavy and bulky, making it inadequate or inconvenient for easy handling by the operator. In addition, the conventional magnetic base, which is of block form, is relatively unstable when placed on an object for supporting a post or arm member to which a relatively large or heavy measuring instrument is mounted. Furthermore, a considerable reduction in the attractive capability of the permanent magnet has been encountered with the prior-art magnetic retainer assembly while in use in which attachment and detachment are repeated.
It should also be noted that needs exist for deformable magnetic retainers which can readily be applied to, for example, a corrugated surface of a magnetizable object to magnetically retain it or an angular junction of two or more magnetizable parts to magnetically hold them together, or to nip a magnetizable article on its two opposed surfaces to magnetically grip it. Conventional deformable magnetic retainers employ a deformable material in which particles of a permanent magnet material are uniformly distributed. These retainers have, however, been of limited utility because of their inability to undergo a high degree of deformation. When subjected to such deformation, cracks tends to form therein. Furthermore, the known deformable magnetic retainers are either relatively short in serve life or poor in magnetic attaction capability.